Rotors for turbomachines are known in various designs. A generic rotor includes a blade ring which has multiple rotor blades having blade platforms engaged flush with one another. The blade platforms are in this case each situated in the radial direction between the blade and the blade root of the individual rotor blades and form an inner delimitation of the flow path through the turbomachine when the rotor is installed. The coordination of the vibration behavior of bladed rotors is in this case of outmost importance for a design of a turbomachine. In thermal gas turbines such as jet engines, in particular, which are operated in different speed ranges, the frequency detuning is very difficult. Known methods for frequency detuning propose the provision of rotor blades having different individual frequencies. This usually takes place by adding or removing masses. For this purpose, bore holes or pockets, which are subsequently filled with additional matter of a different type, are introduced into the blades of the rotor blades, as described in DE 10 2007 014 886 A1, for example. Alternatively, it is known from WO 03/062606 A1 that the additional matter is applied as coating on the pressure side and/or the suction side of the rotor blade in the area of the blade tip of the blade in order to obtain differently designed rotor blades having their respective different natural vibrations.